Saturday, April 26, 2008

Air Conditioning, Is It Really Necessary?

The advent of air conditioning has brought countless benefits to the world; human comfort being probably the main benefit we think of whenever we talk about air conditioning. The hot summer season spells inconvenience and a lot of sweat at work and at home without air conditioning. On the other hand, the coming of winter signifies torment with the unbearably frigid temperatures that come along with it if one is without air conditioning.

Most office buildings and industrial plants in most countries of the world have air conditioning facilities installed to provide good working environment for their work forces. In temperate countries, modern premises are well equipped with sufficient air conditioning systems to cool both workers and products, especially when the temperature is high all year round.

An office air conditioning system can provide full control of temperature, dust, humidity and air distribution unlike most home cooling systems. Basically, an office air conditioner resembles a room air conditioner where a refrigerant passes through a cooling coil and refrigeration occurs in a separate unit. Multi-storey office buildings on the other hand require larger units and use water-cooled condensers since air-cooled condensers are often not available. A separate cooling tower is usually included in water-cooled condensers in order to conserve water. The condenser water in the cooling tower is cooled by evaporation into the outside air. Sometimes offices have different temperature requirements for different sections. In cases where different sections demand varying temperature settings, two air ducts are used. One duct carries cool air while the other duct carries warm air. Upon entering a space, air is then mixed to the desired temperature as indicated by the thermostat setting. Since space is valuable in any office building, all possibilities are exhausted in order to save this. That's why duct systems with significantly much higher air velocity and air pressure compared with those used in home systems are being used specifically for office air conditioning.

Today's modern school buildings have been provided with cooling equipment as well. Some building designs expose the indoor environment to the heat of the sun especially during the summer season. There are many one-storey schools with huge east and west glass walls and a lot of solar exposure through the roof and windows. These types of buildings necessitate the use of air conditioning units for effective teaching and learning, especially during the hot and humid months of summer. Studies show that there is a correlation between the use of air conditioning and the significant decline in absenteeism during the hot summer days. There is also inconclusive evidence that points to the decrease in respiratory ailments where air conditioning is used in offices and schools.

Air conditioning, whether to provide cool air during hot weather or warm air during cold weather, has proven to be one of the most valuable discoveries of our time. It has provided us with comfort and ease in our daily lives. Those who work in offices and teachers and students in schools can concentrate on their respective tasks because of the comfort that air conditioning provides. Can you imagine working in your office without it? You might just freak out!

Michael Russell

Your Independent guide to Air Conditioning

Keeping Cooling Towers and Heat Exchangers Clean

Filtration Systems Can Reduce Maintenance and Downtime.

To strike an interesting analogy, your cooling tower and heat exchanger is what the lungs and heart are to the human body; when either aren't working properly, it effects other parts of the body and your health suffers. Similarly, when your cooling tower and heat exchanger isn't clean, the heat exchange process doesn't work efficiently and the health of your production and process cooling system suffers.

Process cooling systems that rely on cooling towers to dissipate heat from process cooling water accomplish this by drawing massive volumes of air into the cooling tower as the water travels through the fill material on its way back to the basin. Through the natural evaporative process, heat is dissipated from the water before it reaches the water basin from which it is re-circulated through the chiller then through the heat exchanger and back again (kind of like when you sweat while working and letting the air evaporate the perspiration to cool you down). It is important to realize that cooling towers are gigantic air scrubbers that capture all airborne debris that happen to be floating nearby, and if your system doesn't have effective filtration, the debris can clog the fill and get circulated and trapped in the heat exchanger where it can build-up, restrict water flow and cause your process equipment to malfunction due to overheating.

An example of this is illustrated by a major automotive assembly facility that had faced periodic downtime due to their robotic welding systems not holding tolerances and causing quality problems. After the robotic technicians spent several days trying to initially solve the problem, one of the maintenance workers opened the heat exchanger and discovered that it was impacted with cottonwood seed, insects and other debris - flow had been reduced and the robotic equipment was running hot. Now you might be asking yourself, whey didn't they have some sort of filtration equipment? The answer is simple; at the time the facility was built, the ambient conditions in that area didn't require a filtration system. However, as the years went by and the area became more developed and cottonwood tree populations grew, the need eventually surfaced.

The interesting thing to note about this situation is that even though cleaning the heat exchanger got the robotic welding system back on-line and running at peak performance, it didn't solve the problem. In fact, cleaning heat exchangers is like taking a cold capsule to relieve the symptoms of a cold. Unless you treat the root cause of the problem, the cooling system will suffer time and again. The root cause in this case and in most heat exchanger fouling situations is the cooling tower - stop the debris from getting into the cooling tower and it will protect the entire process cooling system including fill, cooling water, chiller and heat exchanger. With the proper filtration technology, your process cooling system will stay clean and running efficiently all season long.

Selecting The Right Filtration System

It is important to realize that optimizing the ecology and operational efficiency of your evaporative cooling system is best accomplished by combining a chemical treatment regimen with some type of filtration. The reason is that chemical treatment specifically targets suspended solids and particulates of 40 microns and below, while filtration systems are designed to stop larger debris, especially the kind that causes system clogging and fouling.

For cooling tower filtration, there are two general technologies: Water Based Systems for which there are a few different variations and Air Intake Filtration Systems. With water-based systems, the choices include basic water strainers that remove debris by simply passing water through a mesh strainer; sand filtration systems that remove debris by passing the water through sand and centrifugal separators that spin the water and remove the debris through centrifugal action. In contrast, Air Intake Filter Systems remove the debris by filtering the air as it is being drawn into the cooling tower, keeping the debris out of the system in the first place. When considering your filtration options, the following questions should be asked.

  • What is the cost associated with downtime due to heat exchanger or cooling tower fouling or clogging? (Knowing this will help you justify your filtration system cost)
  • What type of debris is most problematic (can you see it or is it microscopic)?
  • Specifically what part of the system does the filter protect?
  • Which system provides the greatest filtration surface area (this can directly impact frequency of cleaning - the smaller the filter the more frequently it needs cleaning)
  • Can the system be installed without shutting down the cooling tower? (If the cooling tower must be shut down for installation, you need to factor lost productivity into the cost of your filtration system if it's not being installed during shutdown periods.)
  • What is the cost associated with both the filter and installation?
  • How easy is the system to install and maintain?
Answering the above questions will help you to fully understand your options and to make the best choice for your operation.

In the case of the automotive manufacturer, the solution they selected was the Air Intake Filter system. The reason was that they needed a system that would protect their entire process cooling system including fill material, cooling water, chiller and heat exchanger. When they evaluated water-based systems, they discovered that the options provided varying degrees of protection for the chiller and heat exchanger but didn't protect the cooling tower where the root of their problem was. If they had selected a water-based system, their cooling tower would have still drawn airborne debris into both the fill and water where the water filter would have captured the debris before it circulated throughout the system. From a maintenance standpoint, that would have solved the heat exchanger problem but it would have done little to reduce maintenance on the cooling tower. Further, when they compared the cost of water based filtration versus air intake filtration technologies, Air Intake Filtration was found to be the more cost effective approach for their operation.

If you are not currently using a filtration system as part of your process cooling system, then any filtration technology will give you more protection than you have now, however, selecting a solution best suited to your operation requires that you know what kind of debris is the problem and where it is getting into the system. As a rule of thumb, " don't select a small debris solution to solve a large debris problem". Conversely, "don't select a large debris solution to solve a small debris problem". There is clearly a place for both water based filtration and air intake filtration - be sure you're selecting the right filtration for your specific need.

If you are looking to protect only your chiller and heat exchanger from airborne debris, then one of the water-based filtration technologies in combination with a good water treatment program can help you manage the debris that gets into the cooling water. If on the other hand, you're looking for full process cooling system protection, then you should look at Air Intake Filtration - It will stop the debris from getting into your system in the first place.

Air Solution Company developed and patented the first Air Intake Filter specifically engineered to mount to the outside of cooling towers and other HVAC equipment for purposes of stopping the debris before it entered into the system. Since that time, Air Solution Company has been manufacturing and has introduced a variety of other innovative filter systems including its new Fine Mesh Filter which is engineered for use on small and medium size refrigeration coils and machine fan intake housing units. Air Solution Company Randy Simmons is with Air Solution Company, author of articles can be reached at http://www.airsolutioncompany.com

Important Information On The Cooling Tower Water Treatment

When you have chosen to use the cooling tower water treatment system, it is most important to remember to not ignore the maintenance required. The water carries bacterial growth in it whether it flows through the faucet or if it is flowing through a cooling tower. If this water is not treated as soon as possible, it can rust and corrode and deposits will form inside the water treatment equipment. This reason makes the cooling tower water treatment system so very important.

Problems From Not Maintaining The Cool Tower

When you do not keep up the proper maintenance on you cooling tower water system, you will find that many different problems will come up. These problems can include scale formation, corrosion, and biological fouling.

Problems With Scale Formation

Scale is what is formed when wet solids get clogged in the pipes. This scale is made from heat and cold water that contains a very high mineral content. These deposits will continue to build up over time. If these scale deposits start to form on a heat exchange surface, they will eventually clog the passages and slow the system down. The cooling tower can also be affected by the scale deposits. If the deposits block the flow of the basin or fill in the cooling tower, problems arise.

Choosing to use a cooling tower water treatment system will help to stop the problems of scale deposits. It is a very budget friendly way for you to treat the problems you are having but also to lower the maintenance and the cost of maintenance on the cooling tower system itself. The majority of money that is spent each year is on the removal of the scale deposits from the inside.

Inside Corrosion

When metal starts to dissolve, you have what is known as corrosion. Oxidation effects break the metal down significantly. The breakdown will cause the system to degrade at a faster rate than normal. The major point being that when the metal starts to break down, the strength of the metal and the thickness off the metal are reduced. The structure of the metal can no longer stand up to the pressure that it was designed for and pits and craters can form in the metal.

A cooling tower system will help to stop the corrosion from happening. The better of the treatments for corrosion is the ozone treatment. There are also other methods that work just as good.

Problems With Biological Fouling

Problems with biological fouling occur when the water has not been used and left for long periods of time. When the water is left unattended, it has the potential to form bacteria, fungus, algae, and protozoa. The microorganisms will eventually get to large proportions in the water and will cause a biological film to form on the surface of the water. This film is very hard to get rid of. This is what is known as biological fouling.

The biological fouling problems are commonly known to be the worst problem that you can encounter with the cooling tower system. The problems that can occur with biological fouling are low heat transfer, the fill can stop working properly, the water flow can be restricted or blocked, or corrosion can occur from the microorganisms present. It can also result in health problems for the humans that are using it.

The use of a cooling tower water system helps to get rid of this particular problem. When you purchase a good system, it will remove the bacteria, viruses, fungus, and any other organisms that should not be in the water. The cooling system will help the fouling that is a problem with the biological affects in the water to not occur. When these nasty things are removed from the water, it will definitely improve the quality of the water and also the flow of the water through the tower.

You can also find more information on drinking purification and water treatment. eWaterTreatmentSystems.com is a comprehensive resource for water treatment with information on reviews, reverse osmosis and how it works.